It all depends on your goal. If you tend to look like a marathon runner, then keep on running. If you want a sprinter or bodybuilder body, try using HITT (high intensity interval training). The ideal HITT session last for 20 – 30 minutes. If you go longer then that, you are just burning yourself out. Start with intervals of 3 minutes at low intensity then 15 seconds at high intensity. Eventually you want to work your way up to 30 seconds of explosive intensity. I prefer doing HITT on a hill or a stationary bike. If you are beginner, try starting this twice a week and build up to your non weight training days. This cardio method will help you shed the stubborn fat from last X-mas.